Search

Alluaudite sulfates are predicted to be high-voltage electrodes for lithium- and sodium-ion batteries. Herein, we provide the first experimental evidence for the operation of sodium cobalt-manganese sulfate, Na2+2δ(Co0.63Mn0.37)2−δ(SO4)3, at potentials higher than 4.0 V vs. Li/Li+. This fact comes as a result of the reduced cationic deficiency, redox properties of Co and Mn and stability of the alluaudite structure during alkali ion intercalation. [ABSTRACT FROM AUTHOR]

This paper presents an approach for analysis and improved usage of digital cultural assets for non-formal learning purposes in digital culture ecosystems. The digital culture ecosystems, their features, and an exemplar are discussed. [ABSTRACT FROM AUTHOR]

The alluaudite-type of structure is of huge research interest as an open matrix ensuring fast alkali-metal ion mobility, a property that could contribute to the development of novel electrode materials for rechargeable alkali-metal ion batteries. In this contribution, we provide new data on the formation of well-crystallized sodium manganese sulfates Na2+δMn2−δ/2(SO4)3 with an alluaudite-type of structure by simple dehydratation of the corresponding dihydrate Na2Mn(SO4)3·2H2O with a kröhnkite-type of structure. The structure of Na2+δMn2−δ/2(SO4)3 is determined on the basis of Rietveld refinement of powder XRD patterns, infrared (IR) and Raman spectroscopy and electron paramagnetic resonance at X- and Q-band frequencies (EPR). From a structural point of view, the release of two H2O molecule from the kröhnkite phase takes place by a transformation of the infinite [Mn(SO4)2(H2O)2] chains into Mn2O10 dimers bounded by distorted Na(1)O-polyhedra. The anhydrous sulfates are able to participate in the electrochemical reaction delivering a reversible capacity of 135 mA h g−1, when they are used as cathode materials in lithium ion cells. The stability of the alluaudite phase Na2+δMn2−δ/2(SO4)3 in the lithium electrolyte solution and the mechanism of the electrochemical reaction are discussed on the basis of ex situ EPR, IR and Raman spectroscopy. This is a first report on electrochemical activity of manganese-based sulfate with an alluaudite-type of structure. [ABSTRACT FROM AUTHOR]

Apoptosis modulation is a procedure amply utilized by intracellular pathogens to favour the outcome of the infection. Nevertheless, the role of apoptosis during infection with Mycobacterium tuberculosis, the causative agent of human tuberculosis, is subject of an intense debate and still remains unclear. In this work, we describe that apoptosis induction in host cells is clearly restricted to virulent M. tuberculosis strains, and is associated with the capacity of the mycobacteria to secrete the 6 kDa early secreted antigenic target ESAT-6 bothunder in vitro and in vivo conditions. Remarkably, only apoptosis-inducing strains are able to propagate infection into new cells, suggesting that apoptosis is used by M. tuberculosis as a colonization mechanism. Finally, we demonstrate that in vitro modulation of apoptosis affects mycobacterial cell-to-cell spread capacity, establishing an unambiguous relationship between apoptosis and propagation of M. tuberculosis. Our data further indicate that BCG and MTBVAC vaccines are inefficient in inducing apoptosis and colonizing new cells, correlating with the strong attenuation profile of these strains previously observed in vitro and in vivo. [ABSTRACT FROM AUTHOR]

The investigation was conducted at IASS "Obraztsov chiflik"-Rousse during the period 2009-2011. Bulgarian and foreign germplasm was the object of study. The objective of the present investigation was to isolate and identify the causes of root rot in alfalfa and to determine the reaction of local and foreign germplasm to the agent. Isolation of the pathogen was performed on KDA and Chapek nutritive medium. Positive results were reported in all germplasm observed. Attack was the lowest in annual plants. [ABSTRACT FROM AUTHOR]

Abstract: Infrared spectra of sulfate doped K2Co(SeO4)2·6H2O and (NH4)2Co(SeO4)2·6H2O and those of ammonium doped K2Co(SO4)2·6H2O and K2Co(SeO4)2·6H2O are presented and discussed in the region of the stretching modes ν 3 and ν 1 of the sulfate ions and in the region of the asymmetric bending modes ν 4 of the NH4 + ions, respectively. The SO4 2− ions matrix-isolated in the selenate matrices (samples K2Co(SeO4)1.98(SO4)0.02·6H2O and (NH4)2Co(SeO4)1.98(SO4)0.02·6H2O) exhibit three bands for ν 3 and one band for ν 1 in agreement with the low site symmetry C 1 of the SeO4 2− host anions. The NH4 + guest ions included in the potassium sulfate matrix are characterized also with three site symmetry components of ν 4 (C 1 site symmetry of the K+ cations). However, the NH4 + guest ions included in the potassium selenate matrix display four bands corresponding to ν 4 instead of three bands expected due probably to some kind of disorder of the ammonium ions. The extent of energetic distortion of the isomorphously included sulfate ions as deduced from the values of Δν 3 (site group splitting), Δν max (the difference between the highest and the lowest components of the stretching modes for the sulfate ions) and Δν 3/ν c (ν c is the centro-frequency of the asymmetric stretching modes) are commented. The spectroscopic experiments reveal that the SO4 2− guest ions are less distorted in the selenate matrices as compared to the same ions in the neat sulfates due to the larger unit-cell volumes of the selenate compounds, i.e. to the smaller repulsion potential at the lattice sites where the guest ions are located. The analysis of the spectra reveals that the band positions of the water librations in the host compounds are affected by the included NH4 + guest ions. The formation of hydrogen bonds between the NH4 + guest ions and the XO4 2− host ions leads to a decrease in the proton acceptor capabilities of the anions (anti-cooperative or proton acceptor competitive effect) and as a result the hydrogen bonds formed by the water molecules weaken on going from the neat potassium compounds to the mixed crystals (the bands corresponding to water librations broaden and shift to lower frequencies). This effect is more pronounced in the case of the selenate matrix due to the stronger proton acceptor capability of the selenate ions than that of the sulfate ones. [Copyright &y& Elsevier]

Abstract: Infrared spectra of K2Zn(SeO4)2·6H2O and (NH4)2Zn(SeO4)2·6H2O containing SO4 2− guest ions and those of K2Zn(SO4)2·6H2O and K2Zn(SeO4)2·6H2O containing NH4 + guest ions are presented and discussed in the region of the stretching modes ν 3 and ν 1 of the sulfate ions and in the region of asymmetric bending modes ν 4 of the NH4 + ions, respectively. The SO4 2− ions matrix-isolated in the selenate matrices (approximately 2mol%) exhibit three bands for ν 3 and one band for ν 1 in agreement with the low site symmetry C 1 of the selenate host ions. The NH4 + guest ions included in the potassium sulfate matrix are characterized also with three site symmetry components of ν 4. However, the ammonium ions in (NH4)2Zn(SeO4)2·6H2O as well as those included in K2Zn(SeO4)2·6H2O display four infrared bands corresponding to ν 4 probably due to some kind of disorder of the ammonium ions. The extent of energetic distortion of the isomorphously included sulfate ions as deduced from the values of Δν 3 (site-group splitting) and Δν max (the difference between the highest and the lowest wavenumbered components of the stretching modes) are commented. The spectroscopic experiments reveal that the SO4 2− guest ions are weaker distorted in the potassium selenate matrix than the same ions in the neat potassium sulfate due to the larger unit-cell volumes of the selenate compounds. However, the SO4 2− guest ions are stronger distorted in the ammonium selenate matrix as compared to the same ions in the neat ammonium sulfate owing to the formation of hydrogen bonds between the SO4 2− guest ions and the NH4 + host ions. The analysis of the spectra shows that the band positions of the water librations in the host potassium compounds are affected by the included ammonium cations. The formation of the hydrogen bonds between the NH4 + guest ions and the XO4 2− host ions leads to a decrease in the proton acceptor capabilities of the anions (anti-cooperative or proton acceptor competitive effect) and as a result the hydrogen bonds formed by the water molecules weaken on going from the neat potassium compounds to the mixed crystals K1.8(NH4)0.2Zn(SO4)2·6H2O and K1.8(NH4)0.2Zn(SeO4)2·6H2O (the bands corresponding to water librations are broadened and shifted to lower frequencies). [Copyright &y& Elsevier]

Abstract: Infrared spectra of compounds with kröhnkite-type infinite octahedral–tetrahedral chains, K2 Me(CrO4)2·2H2O and Na2 Me(SeO4)2·2H2O (Me =Mg, Co, Ni, Zn, Cd), as well as infrared spectra of the title double salts containing matrix-isolated SO4 2− guest ions are presented and discussed in the regions of the X–O stretching modes. The SO4 2− guest ions matrix-isolated in selenate and chromate matrices exhibit four infrared bands corresponding to the four site-group components of the stretching modes in good agreement with the low site symmetry of the host ions (C 1 site symmetry). The values of Δν3 (site-group splitting) and Δνmax (the difference between the highest and the lowest wavenumbered components of the stretching modes) are used as an adequate measure for the extent of energetic distortion of the matrix-isolated SO4 2− guest ions. The influence of different crystal-chemical parameters (Me 2+–OXO3 bond strengths, sizes of the Me 2+ and Me + ions, electronic configurations of the Me 2+ ions, hydrogen bond strengths, and unit-cell volumes of the host compounds) on the extent of energetic distortion of both the host SeO4 2− and CrO4 2− ions, and the SO4 2− guest ions is analyzed. Correlations between the values of Δν3 and Δνmax of the guest ions and both the degree of covalency of the respective Me 2+–OXO3 bonds and the electronic configurations of the Me 2+ ions have been found and will be discussed. For example, the energetic distortion of SO4 2− ions included in the chromate lattices decreases in the order Zn>Cd>Mg as a result of the decreasing covalency of the respective Me 2+–O bonds in the same order (Δν3 have values of 73, 58 and 36cm−1, respectively). Furthermore, the values of Δν3 and Δνmax are larger when the metal ions have CFSE≠0 (crystal field stabilization energy, Co2+, Ni2+). These cations are more resistant to angular deformations of the MeO6 octahedra (i.e. changes in the O–Me–O bond angles), thus facilitating the extent of distortion of the matrix-isolated SO4 2− ions as compared to those having CFSE=0 (Mg2+, Zn2+ and Cd2+). For example, Δν3 and Δνmax of SO4 2− ions matrix-isolated in K2Zn(CrO4)2·2H2O have values of 73 and 163cm−1, and 116 and 207cm−1 in Na2Zn(SeO4)2·2H2O, whereas in the respective nickel lattices Δν3 and Δνmax have values of 88 and 173cm−1 (K2Ni(CrO4)2·2H2O) and 127 and 212cm−1 (Na2Ni(SeO4)2·2H2O). The SO4 2− guest ions included in selenate matrices, Na2 Me(SeO4)2·2H2O, are remarkably much distorted than in chromate ones, K2 Me(CrO4)2·2H2O, as deduced from the values of Δν3 and Δνmax owing to a stronger static field caused by the smaller Na+ ions as compared to that caused by the larger K+ ions. The smaller unit-cell volumes of the selenate host compounds, i.e. the higher repulsion potential at the lattice sites at which the guest ions are situated additionally favor the extent of energetic distortion of the sulfate guest ions in the selenate matrices. [Copyright &y& Elsevier]

Abstract: Infrared spectra of K2Mg(SeO4)2·6H2O and (NH4)2Mg(SeO4)2·6H2O containing SO4 2− guest ions and those of K2Mg(SO4)2·6H2O and K2Mg(SeO4)2·6H2O containing NH4 + guest ions are presented and discussed in the region of the stretching modes ν 3 and ν 1 of the sulfate ions and in the region of the asymmetric bending modes ν 4 of the NH4 + ions. The SO4 2− ions matrix-isolated in the selenate matrices (approximately 5mol%) exhibit three bands for ν 3 and one band for ν 1 in agreement with the low site symmetry C 1 of the SeO4 2− host anions. The NH4 + guest ions included in the potassium matrices are characterized also with three site symmetry components of ν 4 (C 1 site symmetry of the K+ cations). The spectral regions of ν 4 and ν 2 of the SO4 2− guest ions as well as those of ν 1, ν 3 and ν 2 of the NH4 + guest ions could not be analyzed precisely due to the overlapping of these motions with motions of other entities in the structures (for example, the normal modes of water molecules and water librations). The extent of energetic distortion of the isomorphously included ions as deduced from the values of Δν 3 and Δν 4 (site-group splitting for the SO4 2− and NH4 + guest ions, respectively) and Δν max (the difference between the highest and the lowest components of the stretching modes for the sulfate ions) are commented. The spectroscopic experiments show that the degree of energetic distortion of the guest ions is not affected by the guest ion concentration up to 20mol%. It has been established that the SO4 2− guest ions are stronger distorted in (NH4)2Mg(SeO4)2·6H2O than in K2Mg(SeO4)2·6H2O (Δν 3 have values of 34cm−1 in the potassium matrix and 45cm−1 in the ammonium one; samples containing about 5mol% sulfate ions, respectively). The formation of hydrogen bonds between the SO4 2− guest ions and NH4 + host ions increases the electrostatic field strength at the lattice sites where the guest ions are located, thus leading to a larger extent of energetic distortion of the sulfate ions included in (NH4)2Mg(SeO4)2·6H2O. The NH4 + guest ions are stronger distorted in K2Mg(SO4)2·6H2O than in K2Mg(SeO4)2·6H2O (Δν 4 have values of 73cm−1 in the former compound and 66cm−1 in the latter one) owing to the smaller unit-cell volume of the sulfate than that of the selenate (repulsion potential of the lattice). The analysis of the spectra reveals that the band positions of the water librations in the host compounds are affected by the included NH4 + guest ions. The formation of hydrogen bonds between the NH4 + guest ions and the XO4 2− host ions leads to a decrease in the proton acceptor capabilities of the anions (anti-cooperative or proton acceptor competitive effect) and as a result the hydrogen bonds weaken on going from the neat potassium compounds to mixed crystals K1.8(NH4)0.2Mg(SO4)2·6H2O and K1.8(NH4)0.2Mg(SeO4)2·6H2O (the bands corresponding to water librations broaden and shift to lower frequencies). [Copyright &y& Elsevier]

The paper estimates the total value for the community of the cleanup of the Buriganga River. Dhaka, the capital of Bangladesh, was developed on the bank of the Buriganga River in the early 1600s. The river is now near dead mainly due to human interventions. The paper develops a hypothetical cleanup programme to improve the water quality, which will help the overall environment in and around the river. The value of this programme is estimated within the framework of total economic value; non-marketed benefits are measured through a contingent valuation survey and marketed benefits are estimated using market and shadow prices. The findings of the survey suggest that not only are a significant proportion of the residents willing to pay for the cleanup programme, but many are also willing to contribute in non-monetary ways (mainly their time). When the latter contribution is monetised, it represents 60% of the total value for the non-marketed benefits. The marketed benefits are estimated to represent 58% of the overall value of the cleanup programme (US$18.6 million/year). A failure to account for all benefits could lead to a gross underestimation of the desirability of providing public funding for the cleanup of dying rivers. [ABSTRACT FROM AUTHOR]

Introduction: Diabetes mellitus (DM) is estimated to affect 2-37% of COPD patients, results varying widely between studies. DM may also correlate with quality of life and lung function.

Mining inevitably violates the natural environment. The consequences of its functioning for the environment are diverse at different stages of the life of the enterprise. During mineral exploration, environmental damage is generally negligible, localized, and can be relatively easily repaired. Subsequent initial work, both with open pit and underground mining methods, has a more significant impact on the environment, but still less significant than with the development itself. During extraction and enrichment, the main production process, the most noticeable consequences are violation of land resources, pollution by wastewater, changes in hydraulic regime and composition of atmospheric air. The key factor, of course, is not how much land is used for any particular activity, but whether this use can be compatible with maintaining environmental integrity.

Particular species of living organisms contribute to our natural environment in respective particular ways. Joined together, these species form biocenoses, able to run vital natural functions. Biogeocenoses that tightly link living and non-living organisms are the basis of ecosystems, our planet and human beings as biological species in particular, as later ones are fully dependent on the environmental condition. Determining the contributions of specific species and, subsequently, ecosystems is an essential aspect of human environmental policy. Determining the importance and value of biological diversity as well as understanding of its existence is a mandatory element of environmental policy of major industrial corporations and the basis of future economic decisions of all countries.